1. Field of the Invention
The present invention relates to an image processing apparatus reading and performing prescribed process on an image and, more specifically, it relates to an image processing apparatus having a function of reading a plurality of images and arranging the images in a prescribed manner.
2. Description of the Background Art
In an image forming apparatus, there are two methods of reading a plurality of documents. In one method, documents are placed one by one on a platen and read one by one in order. In the other method, an ADF (Auto Document Feeder) is mounted on a document cover of the image forming apparatus, and thereby the documents are fed and read in order.
In the method of reading with ADF, document sheets are set on the apparatus with the document cover closed. Therefore, it is necessary for the user before setting the document to confirm that nothing is placed on the platen.
Japanese Patent Laying-Open No. 2003-198803 (hereinafter referred to as '803 reference) discloses a technique for preventing a reading operation using ADF with a document left on the platen, in which once a document is read using a platen of the document reading apparatus, a reading operation by the ADF is inhibited until ADF itself is once opened and closed.
Current image processing apparatuses have a so-called N-in-1 function (multi-shot function), in which a plurality of (N) document sheets are read and reduced, and reproduced as one image data. This function is convenient for the user in that the document containing a number of sheets can be viewed at a sight and the number of sheets of recording paper can be reduced. Further, other than the printing purpose, this function can be utilized in various and many ways as a plurality of image files can be put together for collective handling.
In order to utilize this function, however, it is necessary to read document sheets in a correct reading order. If a user manually changes sheets of document for reading without using ADF, reading in unintended order may occur due to a mistake by the user forgetting exchange of the document sheets. If read in erroneous order, the resulting print would be a waste of recording paper and if the result is handled as data, correctness of the data is questionable. It becomes necessary for the user to restart the document reading operation from the beginning, which is rather troublesome.
Such a problem can be solved by the use of ADF. The ADF, however, is not free from the possibility of damaging documents. Therefore, for instance, ADF is seldom provided on an image forming apparatus installed in a convenience store, to prevent potential damage to documents. In such a situation, manual feeding of document sheets for reading by the user is unavoidable, possibly leading to the problem described above.
Similar problem may be experienced when document reading order is of importance, such as in the case of forming double-sided copies of single-sided documents.
The technique described in '803 reference is after all a solution when ADF is used. Therefore, the technique is not available when the apparatus is not provided with ADF or when a plurality of document images are to be arranged in a prescribed manner without using ADF.